In patients with chronic kidney disease, the adverse cardiovascular effects of anemia have been well established. New data are emerging to suggest anemia may represent an important treatable cause of cardiac morbidity and mortality in patients with heart failure. To improve the understanding of the problem of anemia in heart failure, it is important to assess the factors that influence the prevalence of anemia and to assess the consistency of the association of anemia and mortality in various populations of patients with heart failure.

A systematic review of the literature was conducted by performing detailed searches of MEDLINE and EMBASE, searching the bibliographies of the articles retrieved during the database search, and conferring with heart-failure experts involved in clinical trials.

Twenty-eight publications from 26 studies that evaluated anemia prevalence with or without effects on mortality in patients with heart failure were identified. The definition of anemia used in each study was tabulated along with pertinent patient characteristics, the prevalence of anemia, and the association between anemia and mortality.

Anemia is common among patients with heart failure. The prevalence of anemia increases with increasing severity of heart failure, declining renal function, and increasing age. Anemia is consistently associated with poorer survival in all patient populations, but there are substantial differences in the patient populations and definition of anemia.

To clarify the prognostic relationship of anemia in patients with heart failure, a standard definition of anemia should be adopted accounting for the menopausal status of women. Age, severity of heart failure, evaluation of kidney function, important comorbidities, and use of angiotensin-converting-enzyme inhibitors should be included, and correctable causes of anemia should be excluded. Inclusion of these factors should allow better definition of the relationship between anemia and prognosis in patients with heart failure.